Stagnospora

Mary Sue,
That is the very first time I've ever seen Stagnospora symptoms on a Nerine. Is it possible that the plant was weakened by becoming too cold? N. sarniensis hybrids begin to suffer if the temperature drops much below 7C. for long periods. N. bowdenii and its hybrids are much hardier and will tolerate wet and a little frost. I can grow these easily in the garden here but N. sarniensis will only survive in the greenhouse with a little additional heat.
Regards.
Den Wilson
Isle of Wight
UK.
Zone 8 (maritime) almost frost-free.